The game was tied at 49 after regulation play, but Temple (8-8, 2-1) scored the first five points, with two free throws from Lavoy Allen and a 3-pointer from Chris Clark, to take a 54-49 lead. Saint Louis (10-8, 1-3) then pulled within a point on two free throws by Paul Eckerle and a jumper by Luke Meyer with 1:54 remaining.
After Clark missed a driving layup, the Billikens had a chance at the last shot with 19 seconds left.
Kevin Lisch, who led Saint Louis with 17 points, including 11 in the second half, got the ball, but Christmas knocked it loose. Lisch then touched it before it went over the half-court line, giving the Owls the ball and the win.
Tommie Liddell was the only other player in double figures, with 12 points for the Billikens.
Saint Louis led 20-18 at halftime and was able to take a 44-39 lead in the second half before Christmas scored eight straight points.
Meyer hit a 3-pointer to tie it. Mark Tyndale made a layup for Temple, and Lisch answered with a short jumper to end regulation with a tie.
Both teams were coming off victories over ranked opponents. Saint Louis beat No. 23 Rhode Island 68-61 on Thursday, and Temple beat No. 20 Xavier 78-59 on Wednesday.
